Jack Dorsey is the 36-year-old mastermind behind Twitter and mobile credit card reader, Square. Last year, when Square became valued at more than $3 billion, Dorsey became a billionaire. He’s been compared to Steve Jobs as one of the most innovative minds in technology.

Jack Dorsey doesn’t have a desk. Instead of a desk, Dorsey uses an iPad. That’s it.

Growing up, Jack Dorsey had a speech impediment. To this day, Dorsey isn’t a comfortable communicator. “I can be silent at some times which unsettles people a bit, because they don’t know what I’m thinking,” he tells 60 Minutes. “Do I feel like I’m an expert in having a normal conversation face-to-face? Absolutely not. That’s just not my natural state.”

Dorsey was really into trains and maps as a kid. He used to spend hours at the train yards. When he was a teenager, he built a way to track emergency vehicles on a map.

He also used to listening to emergency dispatches on a police scanner. Those experiences inspired him to create Twitter. “They’re always talking about where they’re going, what they’re doing and where they currently are,” Dorsey tells 60 Minutes. “And that is where the idea for Twitter came was now we all have these cell phones…And suddenly we could update where I was, what I’m doing, where I’m going, how I feel. And then it would go out to the entire world.”

Dorsey finds it a little offensive when he’s called a nerd. Forbes called him a nerd in a recent article. Even though the publication meant it to be endearing, Dorsey wasn’t pleased. [I found it] insulting,’ Dorsey says. “[That] I’m ‘more of a nerd than Steve Jobs.’ I think the reference was because I was a programmer. So if that is the nerdy way, then guilty. I’m a nerd.

To inspire employees, Dorsey takes them to the Golden Gate Bridge. Specifically, he takes them to Land’s End. He thinks good software should operate like a bridge. People shouldn’t be thinking about the engineering behind it. They should think of it as functional and simple. “We see the bridge as like this perfect intersection between art and engineering. It has pure utility, in that people commute on it every single day,” he says. “When people come to Twitter and they want to express something in the world, the technology fades away.”

Jack Dorsey first moved to Manhattan when he was 19. He aspires to be the city’s mayor someday. “[New York City is] kinda like being in a car in the middle of a thunderstorm, right,” says Dorsey. “Everything is raging around you, but you’re safe inside that car. So New York feels very much to me like that.”